268657640 has 32 divisors (see below), whose sum is σ = 617345280. Its totient is φ = 105175872.

The previous prime is 268657619. The next prime is 268657643. The reversal of 268657640 is 46756862.

It is a junction number, because it is equal to n+sod(n) for n = 268657591 and 268657600.

It is not an unprimeable number, because it can be changed into a prime (268657643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 69572 + ... + 73331.

It is an arithmetic number, because the mean of its divisors is an integer number (19292040).

Almost surely, 2^268657640 is an apocalyptic number.

268657640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

268657640 is an abundant number, since it is smaller than the sum of its proper divisors (348687640).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

268657640 is a wasteful number, since it uses less digits than its factorization.

268657640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142961 (or 142957 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 44.

The square root of 268657640 is about 16390.7791151001. The cubic root of 268657640 is about 645.2575058986.

The spelling of 268657640 in words is "two hundred sixty-eight million, six hundred fifty-seven thousand, six hundred forty".